Insulating film, battery cell, battery, preparing method and device, and electrical device

ABSTRACT

Disclosed is an insulating film, a battery cell, a battery, a method for preparing a battery cell, a device for preparing a battery cell, and an electrical device, wherein the insulating film includes a bottom coverage region and a plurality of alternately arranged first side coverage regions and second side coverage regions; the plurality of first side coverage regions and second side coverage regions are all located on the same side of the bottom coverage region; the first side coverage region includes a bottom masking portion and two side overlapping portions stacked on the bottom masking portion; a first guide groove is formed at the junction of the bottom masking portion and the side overlapping portion, a second guide groove corresponding to the first guide groove is arranged on the side overlapping portion, the second guide groove intersects with the first guide groove, and is set to incline downward.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of International Patent ApplicationNo. PCT/CN2021/116293 filed on Sep. 2, 2021 the disclosures of which isincorporated in their entirety by reference herein

TECHNICAL FIELD

The present application relates to the field of battery technology, andin particular, to an insulating film, a battery cell, a battery, amethod for preparing a battery cell, a device for preparing a batterycell, and an electrical device.

BACKGROUND ART

With the increasing environmental pollution, the new energy industry hasattracted more and more attention. The rechargeable lithium-ionsecondary battery has become an important part of many electronicproducts, energy storage products and electric vehicles. Its performancewill directly affect the promotion and use of these products.

For lithium-ion batteries, in order to prevent water vapor frominfiltrating into the battery cells, an insulating film is usually usedto enclose the battery cell.

However, in the process of enclosing using the insulating film, a creasewill be formed at the folded position, and a gap will be formed at thecrease, which easily leads to capillary action. Especially when thecrease at the bottom comes into contact with the liquid, it is easy forthe liquid to climb up through the crease, and when reaching the end ofthe crease, the liquid will infiltrate between the insulating film andthe case, making the waterproof effect ineffective.

SUMMARY OF THE INVENTION

The present application provides an insulating film, a battery cell, abattery, a method for preparing a battery cell, a device for preparing abattery cell, and an electrical device, which can prevent the liquidfrom being sucked back and infiltrating between the insulating film andthe case.

A first aspect of the present application provides an insulating film;the insulating film includes a bottom coverage region and a plurality ofalternately arranged first side coverage regions and second sidecoverage regions, the total number of the first side coverage regionsand second side coverage regions is equal to the number of sides of thebottom coverage region, and each side of the bottom coverage region isconnected with one of the first side coverage regions or one of thesecond side coverage regions; wherein, the plurality of the first sidecoverage regions and second side coverage regions are located on thesame side of the bottom coverage region to form an accommodating space;

the first side coverage region includes a bottom masking portion and twoside overlapping portions, the bottom edge of the bottom masking portionis connected with one side of the bottom coverage region, and the twoside overlapping portions are stacked on the bottom masking portion, andare respectively connected with the two second side coverage regions onboth sides of the bottom masking portion; and a first guide groove isformed at the junction of the bottom masking portion and the sideoverlapping portion, and a second guide groove corresponding to thefirst guide groove is arranged on the side overlapping portion, thesecond guide groove intersects with the first guide groove, and thesecond guide groove is set to incline downward.

The junction of the bottom masking portion and the side overlappingportion is at the crease position where the liquid will climb up alongthe first guide groove. When the liquid climbs up to the top of thefirst guide groove, it will change its flowing direction along thesecond guide groove inclined downward, so that the liquid sucked backfrom the bottom can be re-directed to the bottom through the secondguide groove, thereby achieving the effect of directional drainage,preventing the liquid from entering the space between the battery celland the insulating film, preventing the liquid from infiltrating intothe surface of the case of the battery cell, and improving thewaterproof effect of the insulating film.

In some embodiments, the second guide groove forms a preset angle withthe first guide groove.

In some embodiments, the preset angle is less than 90 degrees.

The second guide groove forms a preset angle with the first guidegroove, and the above-mentioned preset angle needs to be less than 90degrees, so that the second guide groove is inclined downward to guidethe liquid sucked from the first guide groove to the bottom of theinsulating film, thereby avoiding the liquid from infiltrating into theaccommodating space of the insulating film.

In some embodiments, the bottom masking portion is a trapezoid, and thelength of the bottom edge of the bottom masking portion is greater thanthe length of the top edge of the bottom masking portion to make thefirst guide grooves inclined.

The first guide groove is arranged obliquely, which can reduce thecapillary action and slow down the speed of the liquid climbing up alongthe first guide groove.

In some embodiments, the bottom cover is an isosceles trapezoid.

The isosceles trapezoid can maintain the symmetry of the two sideoverlapping portions on either side of the bottom masking portion.

In some embodiments, the side overlapping portion includes: a triangularregion and a connecting region; wherein, the triangular region iscovered on the bottom masking portion, and the connecting region iscovered on the triangular region;

the first side of the triangular region is connected with a side edge ofthe bottom masking portion to form the first guide groove, the secondside of the triangular region forms the second guide groove, and thethird side of the triangular region is connected with one side of theconnecting region; and the other side of the connecting region isconnected with the adjacent second side coverage region.

The above-mentioned triangular region is a key component for forming thesecond guide groove and the first guide groove, and the triangularregion also plays the role of connecting the bottom masking portion andthe connecting region.

In some embodiments, the third side of the triangular region and oneside of the corresponding connecting region are equal in length, and arealigned and connected.

As a result, the triangular region and the connecting region areconnected integrally, which improves the integrity and leakproofness ofthe insulating film.

In some embodiments, the side of the connecting region connecting thetriangular region intersects with the side connecting the second sidecoverage region.

As a result, the triangular region, the connecting region and the secondside coverage region are seamlessly connected, ensuring the integrity ofthe side overlapping portion covering the bottom masking portion, andthe leakproofness of the connection between the side overlapping portionand the second side coverage region, and ensuring the leakproofness ofthe insulating film.

In some embodiments, an adhesive structure is provided on the side ofthe connecting region close to the bottom masking portion to fix thetriangular region on the bottom masking portion.

In some embodiments, the bottom edge of the bottom masking portion andthe corresponding side of the bottom coverage region are equal inlength, and are aligned and connected; and

the bottom edge of the second side coverage region and the correspondingside of the bottom coverage region are equal in length, and are alignedand connected.

As a result, the existence of gaps between the bottom masking portion,the second side coverage region and the bottom coverage region can beavoided, thereby achieving the purpose of waterproofing.

In some embodiments, the accommodating space is used to enclose batterycells or battery modules.

In some embodiments, the inner wall of the accommodating space is bondedto the battery cell or the battery module.

In some embodiments, the material of the insulating film is a waterproofmaterial.

According to a second aspect of the present application, provided is abattery cell including a case and the above-mentioned insulating film;wherein, the bottom wall of the case is covered with the bottom coverageregion of the insulating film, and the side walls of the case arecovered with the first side coverage region and the second side coverageregion of the insulating film, so that the battery cell is at leastpartially enclosed in the accommodating space of the insulating film.

According to a third aspect of the present application, provided is abattery which includes a plurality of the above-mentioned battery cells.

According to a fourth aspect of the present application, provided is amethod for preparing a battery cell, which comprises:

providing a cell enclosed with a case; and

providing the above-mentioned insulating film for enclosing the case;wherein the bottom coverage region of the insulating film covers thebottom wall of the case, and the first side coverage region and secondside coverage region of the insulating film cover the side walls of thecase, so that the case is at least partially enclosed in theaccommodating space of the insulating film.

According to a fifth aspect of the present application, provided is adevice for preparing a battery cell, which includes:

a first apparatus used for providing a cell enclosed with a case; and

a second apparatus used for providing the above-mentioned insulatingfilm for enclosing the case; wherein the bottom coverage region of theinsulating film covers the bottom wall of the case, and the first sidecoverage region and second side coverage region of the insulating filmcover the side walls of the case, so that the case is at least partiallyenclosed in the accommodating space of the insulating film.

According to a sixth aspect of the present application, provided is anelectrical device including the above-mentioned battery.

DESCRIPTION OF DRAWINGS

In order to illustrate the technical solutions in the embodiments of thepresent application or in the prior art more clearly, the drawings to beused in the embodiments of the present application or in the prior artwill be briefly introduced below. Obviously, the drawings describedbelow are some embodiments of the present application. For those ofordinary skill in the art, other drawings can also be obtained based onthese drawings without any creative work.

The drawings described herein are intended to provide a furtherunderstanding of the present application, and constitute a part of thepresent application. The illustrative embodiments of the presentapplication and the description thereof are for explaining the presentapplication and do not constitute an undue limitation on the presentapplication.

FIG. 1 -A is a schematic structural diagram of an electrical deviceaccording to an embodiment of the present application.

FIG. 1 -B is a schematic structural diagram of a battery according to anembodiment of the present application.

FIG. 1 -C is a schematic structural diagram of a battery moduleaccording to an embodiment of the present application.

FIG. 1 -D is a schematic structural diagram of a battery cell accordingto an embodiment of the present application.

FIG. 2 is a schematic structural diagram of an insulating film accordingto an embodiment of the present application.

FIG. 3 is a first schematic structural diagram of a first side coverageregion in an insulating film according to an embodiment of the presentapplication.

FIG. 4 is a second schematic structural diagram of a first side coverageregion in an insulating film according to an embodiment of the presentapplication.

FIG. 5 is a flow chart of a method for preparing a battery cellaccording to an embodiment of the present application.

FIG. 6 is a block diagram of a device for preparing a battery cellaccording to an embodiment of the present application.

DETAILED DESCRIPTION

In order to make the purposes, technical solutions and advantages of thepresent application clearer, the present application will be describedin further detail below in conjunction with the drawings andembodiments. It should be understood that the specific embodimentsdescribed here are only used to explain the present application, and arethe preferred embodiments of the present application, but are notintended to limit the protection scope of the present application.Therefore, all the equivalent changes made according to the structures,shapes, and principles of the present invention should be within theprotection scope of the present application.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meanings as those commonly understood by those skilled inthe art to which the present application belongs. The terms used in thespecification of the present application are merely for the purpose ofdescribing specific embodiments, but are not intended to limit thepresent application. The terms “including” and “having” and anyvariations thereof in the specification and the claims of the presentapplication as well as the description of the drawings are intended tocover non-exclusive inclusions.

Reference herein to “an embodiment” means that a particular feature,structure, or characteristic described in connection with the embodimentcan be included in at least one embodiment of the present application.The appearance of the phrase “embodiment” in various places in thespecification does not necessarily refer to the same embodiment, nor isit a separate or alternative embodiment that is mutually exclusive withother embodiments. It is explicitly and implicitly understood by thoseskilled in the art that the embodiments described herein may be combinedwith other embodiments.

In the present application, the term “and/or” is only an associationrelationship for describing associated objects, indicating that threerelationships may exist. For example, A and/or B may represent threesituations: A exists alone, both A and B exist, and B exists alone. Inaddition, the character “/” herein generally means that the associatedobjects before and after it are in an “or” relationship.

Furthermore, the terms “first”, “second” and the like in thespecification and the claims of the present application as well as theabove-mentioned description of drawings are used to distinguishdifferent objects, rather than to describe a specific order, and one ormore of these features may be explicitly or implicitly included.

In the description of the present application, unless otherwise stated,“a plurality of” means two or more (including two), and similarly, “aplurality of groups” means two or more groups (including two groups).

In the description of the present application, it should be noted that,unless otherwise expressly specified and limited, the terms “mount”,“connected” and “connecting” should be understood in a broad sense, forexample, “connected” or “connecting” of mechanical structures can referto a physical connection. For example, a physical connection can be afixed connection, such as a fixed connection through fasteners such asscrews, bolts or other fasteners; a physical connection can also be adetachable connection, such as mutual clamping connection or snap-fitconnection; the physical connection can also be an integratedconnection, for example, connection through welding, bonding or integralforming. The “connected” or “connecting” of a circuit structure mayrefer not only to physical connection, but also to electrical connectionor signal connection. For example, it may be direct joining, that is,physical connection, or indirect connection through at least oneintermediate element, as long as the circuits are connected, and it canalso be the internal connection between two elements; in addition to thesignal connection through the circuit, the signal connection can alsorefer to the signal connection through a medium, such as radio waves.For those of ordinary skill in the art, the specific meanings of theabove terms in the embodiments of the present application can beunderstood according to specific situations.

In order to clearly describe the various orientations in the followingembodiments, some words of place can be used, for example, thecoordinate system in FIG. 1 -D defines the various orientations anddirections of the battery, and the x-direction represents the lengthdirection of the battery cell 400 , the y direction is perpendicular tothe x direction in the horizontal plane, indicating the width directionof the battery cell 400 , and the z direction is perpendicular to the xdirection and the y direction, indicating the height direction of thebattery. In addition, the indications of the above-describedx-direction, y-direction, and z-direction, etc. used to describe thedirections of the operation and configuration of the components of thebattery of the present embodiment are not absolute but relative, andalthough these indications are appropriate when the components of thebattery are in the positions shown in the drawings, when these positionsare changed, the directions should be interpreted differently tocorrespond to the changes.

Based on the same understanding of orientations, in the description ofthe present application, the orientational or positional relationshipsindicated by the terms “central,” “machine direction,” “transversedirection,” “length,” “width,” “thickness,” “upper,” “lower,” “front,”“rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,”“inner,” “outer,” “clockwise,” “anticlockwise,” “axial,” “radial,”“circumferential,” etc. are based on the orientational or positionalrelationships shown in the drawings and are only for facilitating thedescription of the present application and simplifying the description,rather than indicating or implying that the apparatus or elementreferred to must have a particular orientation or be constructed andoperated in a particular orientation, and therefore will not beinterpreted as limiting the present application.

A rechargeable battery may be called a secondary battery or a powerbattery. Currently, widely used rechargeable batteries are lithiumbatteries, such as lithium-sulfur batteries, sodium-lithium-ionbatteries or magnesium-ion batteries, but are not limited thereto. Forthe convenience of description, rechargeable batteries may becollectively referred to as batteries herein.

In the present application, a battery is generally composed of aplurality of battery cells connected together, and the battery cell mayinclude a lithium-ion secondary battery, a lithium-ion primary battery,a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ionbattery, or a magnesium-ion battery, etc., which is not limited in theembodiments of the present application. The battery cell may becylindrical, flat, rectangular, or of other shapes, which is also notlimited in the embodiments of the present application. The battery cellsare generally divided into three types according to encapsulatingmanners: cylindrical battery cells, rectangular battery cells, and pouchbattery cells, which are not limited in the embodiments of the presentapplication.

The battery mentioned in the embodiments of the present applicationrefers to a single physical module including one or more battery cellsto provide a higher voltage and capacity. For example, the batterymentioned in the present application may include a battery module, abattery pack, or the like. The battery typically includes a box body forencapsulating one or more battery cells. The box body can preventliquids or other foreign matters from affecting charging or dischargingof the battery cells.

The battery cells include electrode assemblies and electrolytesolutions, and each electrode assembly is composed of a positiveelectrode sheet, a negative electrode sheet and a separator. The batterycells work mainly relying on the movement of metal ions between thepositive electrode sheet and the negative electrode sheet. The positiveelectrode sheet includes a positive current collector and a positiveelectrode active material layer, a surface of the positive currentcollector is coated with the positive electrode active material layer,the positive current collector not coated with the positive electrodeactive material layer protrudes from the positive electrode collectoralready coated with the positive electrode active material layer, andthe positive current collector not coated with the positive electrodeactive material layer is used as a positive tab. Taking a lithium-ionbattery as an example, the material of the positive current collectormay be aluminum, and the positive electrode active material may belithium cobalt oxide, lithium iron phosphate, ternary lithium, lithiummanganate, or the like. The negative electrode sheet includes a negativecurrent collector and a negative electrode active material layer, thesurface of the negative current collector is coated with the negativeelectrode active material layer, the negative current collector notcoated with the negative electrode active material layer protrudes fromthe negative electrode collector already coated with the negativeelectrode active material layer, and the negative current collector notcoated with the negative electrode active material layer is used as anegative tab. The material of the negative electrode current collectormay be copper, and the negative electrode active material may be carbon,silicon, or the like. In order to ensure that no fusing occurs when alarge current passes, there are a plurality of positive tabs which arestacked together, and there are a plurality of negative tabs which arestacked together. The material of the separator may be polypropylene(PP), polyethylene (PE), or the like. In addition, the electrodeassembly may be of a wound structure or a laminated structure, which isnot limited in the embodiments of the present application.

The batteries in the embodiments of the present application can beapplied to various electrical devices that use electrical energy as thepower source. The electrical device here can be, but not limited to,electric vehicles, electric trains, electric bicycles, golf carts,drones, or ships. In addition, the electrical device may be a apparatuspowered only by a battery, or a hybrid apparatus. The battery provideselectrical energy for the electrical device, and drives the electricapparatus to travel through the motor.

For example, as shown in FIG. 1 -A, which is a schematic structuraldiagram of an electrical device according to an embodiment of thepresent application, the electrical device may be a vehicle, which maybe a fuel vehicle, a gas vehicle or a new-energy vehicle. The new-energyvehicle may be an all-electric vehicle, a hybrid electric vehicle, anextended-range electric vehicle, etc. The vehicle includes a battery200, a controller 210 and a motor 220. The battery 200 is configured tosupply power to the controller 210 and the motor 220 and act as theoperating power source and driving power source of the vehicle. Forexample, the battery 200 is configured to meet the working powerrequirements of the vehicle during starting, navigating and running. Forexample, the battery 200 supplies power to the controller 210, thecontroller 210 controls the battery 200 to supply power to the motor220, and the motor 220 receives and uses the power from the battery 200as the driving power of the vehicle, replacing or partially replacingthe driving power provided by the fuel or natural gas for the vehicle.

In order to enable the battery to achieve a higher capacity to meet userequirements, the battery 200 may include a plurality of battery modulesthat are electrically connected with each other. As shown in FIG. 1 -B,the battery 200 includes a first box body 201, a second box body 202 anda plurality of battery modules 300, wherein the first box body 201 andthe second box body 202 are fastened to each other, and a plurality ofbattery modules 300 are arranged in the space enclosed by the first boxbody 201 and the second box body 202. In some embodiments, the first boxbody 201 and the second box body 202 are hermetically connected.

As shown in FIG. 1 -C, the battery module 300 includes a plurality ofbattery cells 400, the plurality of battery cells 400 may beelectrically connected in series, in parallel, or in parallel-series toachieve a higher electrical current or voltage, wherein theparallel-series connection refers to a combination of series connectionand parallel connection. For example, as shown in FIG. 1 -C, the batterycell 400 can be placed vertically, the height direction of the batterycell 400 is consistent with the z direction, the length direction of thebattery cell 400 is consistent with the x direction, and a plurality ofbattery cells 400, along their width direction, are arranged side byside in the y direction; alternatively, the battery cell 400 can be laidhorizontally, the width direction of the battery cell 400 is consistentwith the z direction, the length direction of the battery cell 400 isconsistent with the x direction, and a plurality of battery cells 400can be stacked into at least one layer along the z direction, and eachlayer includes a plurality of battery cells 400 spaced along thex-direction.

In order for those skilled in the art to clearly understand theimprovements in the present application, the overall structure of thebattery cell 400 is first described.

As shown in FIG. 1 -D, the battery cell 400 includes a case 40, anelectrode assembly 30, and an end cover assembly 10. The end coverassembly 10 includes an end cover plate 10′, the end cover plate 10′ isconnected with the case 40 (e.g., by welding) to form the shell of thebattery cell 400, the electrode assembly 30 is disposed in the case 40,and the case 40 is filled with an electrolyte solution. The battery cell400 may be of a cubic or cuboid shape.

According to the actual use requirements, there can be one or moreelectrode assemblies 30. As shown in FIG. 1 -D, at least twoindependently wound electrode assemblies 30 may be provided in thebattery. The electrode assembly 30 may be formed by winding or stackinga first electrode sheet, a second electrode sheet, and a separatorbetween adjacent first and second electrode sheets to form a main body,wherein the separator is an insulator between adjacent first and secondelectrode sheets. In the embodiment, the first electrode sheet isexemplified as a positive electrode sheet and the second electrode sheetas a negative electrode sheet for description. The positive electrodeactive material is coated on the coating region of the positiveelectrode sheet, and the negative electrode active material is coated onthe coating region of the negative electrode sheet. A plurality ofuncoating regions extending from the coating region of the main body arestacked as tabs. The electrode assembly 30 includes two tabs 301, thatis, a positive tab and a negative tab. The positive tab extends from thecoating region of the positive electrode sheet, and the negative tabextends from the coating region of the negative electrode sheet.

The end cover assembly 10 is arranged at the top of the electrodeassembly 30. As shown in FIG. 1 -D, the end cover assembly 10 includesan end cover plate 10′ and two electrode terminals 5, i.e., twoelectrode terminals 5 are a positive electrode terminal and a negativeelectrode terminal respectively. Each electrode terminal 5 is providedwith a corresponding connecting member 20, and the connecting member 20is located between the end cover plate 10′ and the electrode assembly30.

For example, in FIG. 1 -D, the tab 301 of the electrode assembly 30 isat the top, the positive tab is connected with the positive electrodeterminal through a connecting member 20, and the negative tab isconnected with the negative electrode terminal through anotherconnecting member 20. Optionally, the battery cell 400 may include twoend cover assemblies 10, each located at either end of the case 40, andeach end cover assembly 10 is provided with an electrode terminal 5.

An explosion-proof member may also be arranged on the end cover plate10′ to release the gas in the battery cell 400 in time when there is toomuch gas in the battery cell 400 to avoid explosion.

The end cover plate 10′ is provided with an exhaust vent, and theexhaust vent can be arranged in the middle of the end cover plate 10′along the length direction. The explosion-proof member includes apressure relief mechanism 6. The pressure relief mechanism 6 is arrangedon the exhaust vent. Under normal conditions, the pressure reliefmechanism 6 is hermetically installed on the exhaust vent. When thebattery cell 400 expands and the pressure inside the shell rises toexceed the preset value, the pressure relief mechanism 6 is actuated toopen, and the gas is released outward through the pressure reliefmechanism 6.

In some embodiments, as shown in FIG. 1 -D, the end cover plate 10′ isprovided with a through hole for injecting the electrolyte solution intothe battery cell 400, and the through hole can be round, elliptical,polygonal or of other shapes, and can extend along the height directionof the end cover plate 10′. The end cover plate 10′ is provided with aliquid injection member 2 for closing the through hole.

As shown in FIG. 2 to FIG. 4 , an embodiment of the present applicationprovides an insulating film for enclosing a battery cell 400. Theinsulating film includes a bottom coverage region 210 and a plurality ofalternately arranged first side coverage regions 220 and second sidecoverage region 230, the bottom coverage region 210 is used to cover thebottom of the battery cell 400; the plurality of alternately arrangedfirst side coverage regions 220 and second side coverage region 230 areused to cover the side surface of the battery cell 400. The total numberof the first side coverage regions 220 and second side coverage regions230 is equal to the number of sides of the bottom coverage region 210,and each side of the bottom coverage region 210 is connected with afirst side coverage region 220 or a second side coverage region 230, soas to ensure that the bottom coverage region 210 can be seamlesslyconnected with the first side coverage region 220 and the second sidecoverage region 230.

In the embodiments of the present application, the plurality of firstside coverage regions 220 and second side coverage regions 230 are alllocated on the same side of the bottom surface coverage region 210 toform an accommodating space. As shown in FIG. 2 , the accommodatingspace is used to accommodate the battery cell 400.

In the embodiments of the present application, the first side coverageregion 220 includes a bottom masking portion 221 and two sideoverlapping portions 222, wherein the bottom edge of the bottom maskingportion 221 is connected with one side of the bottom coverage region210, so as to realize the connection of the bottom coverage region 210with the first side coverage region 220; the two side overlappingportions 222 are stacked on the bottom masking portion 221, and arerespectively connected with the two second side coverage regions 230 oneither side of the bottom masking portion 221, so as to realize theconnection of the first side coverage region 220 with the second sidecoverage region 230.

Further, the two side overlapping portions 222 stacked on the bottommasking portion 221 are at least partially overlapped, so that thebottom of the resulting accommodating space is sealed, thereby providinga waterproof effect.

In order to prevent capillary action at the crease position, which cancause the liquid to be sucked back into the accommodating space, in theinsulating film provided by the embodiment of the present application, afirst guide groove 310 is formed at the junction of the bottom maskingportion 221 and the side overlapping portion 222, and the sideoverlapping portion 222 is provided with a second guide groove 320corresponding to the first guide groove 310 , the second guide groove320 intersects with the first guide groove 310 , and the second guidegroove 320 is inclined downward.

As shown in FIG. 3 , the junction of the bottom masking portion 221 andthe side overlapping portion 222 is at the crease position where theliquid will climb up along the first guide groove 310. When the liquidclimbs up to the top of the first guide groove 310, it will change itsflowing direction along the second guide groove 320 inclined downward,so that the liquid sucked back from the bottom can be re-directed to thebottom through the second guide groove 320, thereby achieving the effectof directional drainage, preventing the liquid from entering the spacebetween the battery cell 400 and the insulating film, preventing theliquid from infiltrating into the surface of the case of the batterycell 400, and improving the waterproof effect of the insulating film.

In the embodiments of the present application, the second guide groove320 forms a preset angle with the first guide groove 310, and theabove-mentioned preset angle needs to be less than 90 degrees, so thatthe second guide groove 320 is inclined downward to guide the liquidsucked from the first guide groove 310 to the bottom of the insulatingfilm, thereby avoiding the liquid from infiltrating into theaccommodating space of the insulating film. In practical applications,the value of the preset angle determines the degree of inclination ofthe second guide groove 320 and the first guide groove 310, and thedegree of inclination determines the drainage effect. The greater thedegree of inclination of the second guide groove 320 and the first guidegroove 310, the better the drainage effect.

In order to further reduce capillary action, in the embodiments of thepresent application, the bottom masking portion 221 is a trapezoid, andthe length of the bottom edge of the bottom masking portion 221 isgreater than the length of the top edge of the bottom masking portion221, so that the first guide groove 310 is inclined, thereby reducingcapillary action and slowing down the speed of the liquid climbing upalong the first guide groove 310.

In order to maintain the symmetry of the two side overlapping portions222 on either side of the bottom masking portion 221, in the embodimentsof the present application, the above-mentioned inverted trapezoid is anisosceles trapezoid.

In the embodiments of the present application, in order to form theabove-mentioned second guide groove 320 and first guide groove 310, theside overlapping portion 222 includes a triangular region 2221 and aconnecting region 2222, wherein the triangular region 2221 covers thebottom masking portion 221, the connecting region 2222 covers thetriangular region 2221, the first side of the triangular region 2221 isconnected with a side edge of the bottom masking portion 221 to form thefirst guide groove 310, and the second side of the triangular region2221 forms the second guide groove 320, the third side of the triangularregion 2221 is connected with one side of the connecting region 2222;and the other side of the connecting region 2222 is connected with theadjacent second side coverage region 230.

From FIG. 3 and FIG. 4 , it can be seen that the above-mentionedtriangular region 2221 is a key component for forming the second guidegroove 320 and the first guide groove 310, and the triangular region2221 also serves to connect the bottom masking portion 221 and theconnecting region 2222. Also, the third side of the triangular region2221 and the corresponding side of the connecting region 2222 are equalin length, and are aligned and connected, so that the triangular region2221 and the connecting region 2222 are connected integrally, whichimproves the integrity and leakproofness of the insulating film.

As shown in FIG. 4 , the side of the connecting region 2222 connectingthe triangular region 2221 intersects with the side connecting thesecond side coverage region 230, that is, the third side of thetriangular region 2221 intersects with the side of the second sidecoverage region 230, thereby making the triangular region 2221, theconnecting region 2222 and the second side coverage region 230seamlessly connected, ensuring the integrity of the side overlappingportion 222 covering the bottom masking portion 221 and theleakproofness of the connection of the side overlapping portion 222 andthe second side coverage region 230, and ensuring the leakproofness ofthe insulating film.

The first side coverage region 220 including the bottom masking portion221 and the two side overlapping portions 222, and the second sidecoverage region 230 are alternately arranged on the same side of thebottom coverage region 210; and the bottom masking portion 221 and theadjacent second side coverage regions 230, in conjunction with thebottom coverage region 210, can form an accommodating space foraccommodating battery cells. In addition, the two side overlappingportions 222 are stacked on the bottom masking portion 221, and the twoside overlapping portions 222 are respectively connected with theadjacent second side coverage regions 230, therefore achieving an effectof sealing the accommodating space, which improves the waterproofperformance of the insulating film and achieves the purpose of makingthe battery waterproof

In practical applications, the above connection mode and stacking modecan be determined according to the actual situation. For example, thebottom masking portion 221 and the second side coverage region 230 arerespectively connected with the bottom coverage region 210 integrally,the bottom masking portion 221 is connected with the triangular region2221 integrally, the triangular region 2221 is connected with theconnecting region 2222 integrally, and the connecting region 2222 isconnected with the second side coverage regions 230 integrally; inaddition, the side of the connecting region 2222 close to the bottomcoverage region 221 is provided with an adhesive structure to fix thetriangular region 2221 on the bottom masking portion 221.

In the embodiments of the present application, in order to facilitatefixing the battery cell 400 in the accommodating space of the insulatingfilm, an adhesive structure may be provided on the side of theinsulating film close to the accommodating space to bond the insulatingfilm onto the battery cell 400. Of course, any other manners that canrealize the fixed connection between the battery cell 400 and theinsulating film fall within the protection scope of the presentapplication.

Similarly, in order to improve the waterproofness of the insulating filmand ensure the integration of various components in the insulating film,the bottom edge of the bottom masking portion 221 and the correspondingside of the bottom coverage region 210 are equal in length, and arealigned and connected; and the bottom edge of the second side coverageregion 230 and the corresponding side of the bottom coverage region 210are equal in length, and are aligned and connected. As a result, theexistence of gaps between the bottom masking portion 221, the secondside coverage region 230 and the bottom coverage region 210 can beavoided, thereby achieving the purpose of waterproofing.

In the embodiments of the present application, the height of theinsulating film is greater than the height of the battery cell 400.Specifically, the height of the connecting region 2222 and the secondside covering region 230 is greater than the height of the battery cell400, thereby achieving the purpose of waterproofing along the heightdirection for the whole battery cell 400.

In practical applications, in addition to the connections betweendifferent parts inside the insulating film, the inner wall of theaccommodating space in the insulating film also needs to be bonded andconnected with the battery cells 400, so that the insulating film andthe battery cells 400 can be relatively fixed. The specific bondingpositions and bonding methods are not particularly limited in theembodiments of the present application.

In the embodiments of the present application, in addition to enclosingthe battery cells 400, the accommodating space of the insulating filmcan also enclose a battery module 300 composed of a plurality of batterycells, and the plurality of battery cells 400 can be connected indifferent ways.

In actual enclosing of the battery module 300, the bottom coverageregion 210 of the insulating film covers the bottom of the batterymodule 300; the plurality of first side coverage regions 220 and secondside coverage regions 230 cover the sides of the battery module 300, andthe battery module 300 is enclosed in the accommodating space.

The specific structure of the insulating film is the same as that forenclosing the battery cell 400, which will not be explained here. Inaddition, the inner wall of the accommodating space in the insulatingfilm also needs to be bonded and connected with the battery module 300to realize the relative fixing between the insulating film and thebattery module 300.

In the embodiments of the present application, the battery cell 400 orthe battery module 300 is enclosed with the insulating film, whichprovides not only an insulating effect, but also a waterproof effect,and also features low cost and small occupied space. In addition, byproviding the second guide groove 320 and the first guide groove 310,even if the liquid at the bottom climbs up through the first guidegroove 310, after it reaches the junction of the first guide groove 310and the second guide groove 320, under the action of gravity and thecapillary action of the second guide groove 320, the climbing directionof the liquid is changed and the liquid flows down to the bottom alongthe second guide groove 320, thereby preventing the liquid frominfiltrating into the surface of the case of the battery cell 400 or thebattery module 300 and avoiding corrosion of the case.

It should be emphasized that the material of the insulating film is awaterproof material. For example, the insulating film is composed of asubstrate and an adhesive layer, wherein the substrate can bepolyethylene, polypropylene, polyethylene terephthalate, polyamide,styrene-acrylate copolymer, polystyrene, polyamide and other highmolecular materials; the adhesive layer can be acrylate, epoxy resin,polyurethane, amino resin, phenolic resin and other high molecularmaterials.

In practical applications, the thickness of the insulating film may be25 to 400 μm, the thickness of the optional substrate may be 20 to 200μm, such as 50 μm, and the thickness of the adhesive layer may be 5 to200 μm, such as 20 μm.

In another aspect, an embodiment of the present application alsoprovides a battery cell. The battery cell 400 includes a case and theabove-mentioned insulating film, and as shown in FIG. 2 , the bottomwall of the case is covered with the bottom coverage region 210 of theinsulating film, the side walls of the case are covered with the firstside coverage region 220 and the second side coverage region 230 of theinsulating film, so that the battery cell 400 is at least partiallyenclosed in the accommodating space of the insulating film. The specificstructure and arrangement position of the insulating film have beendescribed in detail in the above-mentioned embodiments, which will notbe repeated in this embodiment.

In another aspect, the present application further provides a batterywhich includes a plurality of the above-mentioned battery cells 400. Thespecific structure of the battery cell 400 has been described in detailin the above-mentioned embodiments, which will not be repeated in thisembodiment.

To sum up, in the battery provided by the embodiments of the presentapplication, by arranging the above-mentioned battery cells, the case ofthe battery cell is covered with the insulating film outside, which, inaddition to an insulating effect, provides capillary action, therebyimproving the waterproof effect of the insulating film.

In another aspect, the present application also provides a method forpreparing a battery cell. As shown in FIG. 5 , the method for preparinga battery cell may include the following steps:

Step S510, providing a cell enclosed with a case;

Step S520, providing the above-mentioned insulating film for enclosingthe case; wherein the bottom coverage region of the insulating filmcovers the bottom wall of the case, and the first side coverage regionand second side coverage region of the insulating film cover the sidewalls of the case, so that the case is at least partially enclosed inthe accommodating space of the insulating film.

The specific details of the above-mentioned method for preparing batterycells have been described in detail in the corresponding battery celland insulating film embodiments, so they will not be repeated here.

In another aspect, the present application also provides a device forpreparing a battery cell. Referring to FIG. 6 , a block diagram of adevice for preparing a battery cell according to an embodiment of thepresent application is shown. As shown in FIG. 6 , the device 600 forpreparing a battery cell may include:

a first apparatus 610 used for providing a cell enclosed with a case;

a second apparatus 620 used for providing the above-mentioned insulatingfilm for enclosing the case; wherein the bottom coverage region of theinsulating film covers the bottom wall of the case, and the first sidecoverage region and second side coverage region of the insulating filmcover the side walls of the case, so that the case is at least partiallyenclosed in the accommodating space of the insulating film.

The specific details of the above-mentioned device for preparing batterycells have been described in the corresponding battery cell andinsulating film embodiments, so they will not be repeated here.

In another aspect, the present application further provides anelectrical device including the afore-mentioned battery; the battery isused for providing electric energy. The specific structure and workingprinciple of the battery have been described in detail in theabove-mentioned embodiments, which will not be repeated in thisembodiment.

The above-mentioned protected subjects and the features in theembodiments of the present application can draw reference from eachother. Where the structure permits, those skilled in the art can alsoflexibly combine the technical features in different embodiments to formmore embodiments.

The above provides a detailed introduction to an insulating film, abattery cell, a battery, a method for preparing a battery cell, a devicefor preparing a battery cell, and an electrical device provided by thepresent application. The principles and embodiments of the presentapplication are described herein by using specific embodiments, and thedescriptions of the above embodiments are only used to help understandthe methods and core ideas of the present application. It should benoted that those of ordinary skill in the art may further make numerousvariations and improvements to the present application without departingfrom the principle of the present application, and all the variationsand improvements fall within the protection scope of the claims of thepresent application.

1. An insulating film, wherein the insulating film includes a bottomcoverage region and a plurality of alternately arranged first sidecoverage regions and second side coverage regions, the total number ofthe first side coverage regions and second side coverage regions isequal to the number of sides of the bottom coverage region, and eachside of the bottom coverage region is connected with one of the firstside coverage regions or one of the second side coverage regions;wherein, the plurality of the first side coverage regions and secondside coverage regions are all located on the same side of the bottomcoverage region to form an accommodating space; the first side coverageregion includes a bottom masking portion and two side overlappingportions, the bottom edge of the bottom masking portion is connectedwith one side of the bottom coverage region, and the two sideoverlapping portions are stacked on the bottom masking portion, and arerespectively connected with the two second side coverage regions on bothsides of the bottom masking portion; and a first guide groove is formedat the junction of the bottom masking portion and the side overlappingportion, and a second guide groove corresponding to the first guidegroove is arranged on the side overlapping portion, the second guidegroove intersects with the first guide groove, and the second guidegroove is set to incline downward.
 2. The insulating film according toclaim 1, wherein the second guide groove forms a preset angle with thefirst guide groove.
 3. The insulating film according to claim 2, whereinthe preset angle is less than 90 degrees.
 4. The insulating filmaccording to claim 1, wherein the bottom masking portion is a trapezoid,and the length of the bottom edge of the bottom masking portion isgreater than the length of the top edge of the bottom masking portion tomake the first guide grooves inclined.
 5. The insulating film accordingto claim 4, wherein the bottom masking portion is an isoscelestrapezoid.
 6. The insulating film according to claim 1, wherein the sideoverlapping portion includes: a triangular region and a connectingregion; wherein, the triangular region is covered on the bottom maskingportion, and the connecting region is covered on the triangular region;the first side of the triangular region is connected with a side edge ofthe bottom masking portion to form the first guide groove, the secondside of the triangular region forms the second guide groove, and thethird side of the triangular region is connected with one side of theconnecting region; and the other side of the connecting region isconnected with the adjacent second side coverage region.
 7. Theinsulating film according to claim 6, wherein the third side of thetriangular region and the corresponding side of the connecting regionare equal in length, and are aligned and connected.
 8. The insulatingfilm according to claim 6, wherein the side of the connecting regionconnecting the triangular region intersects with the side connecting thesecond side coverage region.
 9. The insulating film according to claim6, wherein an adhesive structure is provided on the side of theconnecting region close to the bottom masking portion to fix thetriangular region on the bottom masking portion.
 10. The insulating filmaccording to claim 1, wherein the bottom edge of the bottom maskingportion and the corresponding side of the bottom coverage region areequal in length, and are aligned and connected; and the bottom edge ofthe second side coverage region and the corresponding side of the bottomcoverage region are equal in length, and are aligned and connected. 11.The insulating film according to claim 1, wherein the accommodatingspace is used for enclosing a battery cell or a battery module.
 12. Theinsulating film according to claim 11, wherein the inner wall of theaccommodating space is bonded to the battery cell or the battery module.13. The insulating film according to claim 1, wherein the material ofthe insulating film is a waterproof material.
 14. A battery cell,comprising a case and the insulating film of claim 1; wherein, thebottom wall of the case is covered with the bottom coverage region ofthe insulating film, and the side walls of the case are covered with thefirst side coverage region and the second side coverage region of theinsulating film, so that the battery cell is at least partially enclosedin the accommodating space of the insulating film.
 15. A battery,comprising a plurality of battery cells of claim
 14. 16. A method forpreparing a battery cell, including: providing a cell enclosed with acase; and providing the insulating film of claim 1 for enclosing thecase; wherein the bottom coverage region of the insulating film coversthe bottom wall of the case, and the first side coverage region andsecond side coverage region of the insulating film cover the side wallsof the case, so that the case is at least partially enclosed in theaccommodating space of the insulating film.
 17. A device for preparingbattery cell, comprising: a first apparatus used for providing a cellenclosed with a case; and a second apparatus used for providing theinsulating film of claim 1 for enclosing the case; wherein the bottomcoverage region of the insulating film covers the bottom wall of thecase, and the first side coverage region and second side coverage regionof the insulating film cover the side walls of the case, so that thecase is at least partially enclosed in the accommodating space of theinsulating film.
 18. An electrical device, comprising the battery ofclaim
 15. 19. The insulating film according to claim 2, wherein thebottom masking portion is a trapezoid, and the length of the bottom edgeof the bottom masking portion is greater than the length of the top edgeof the bottom masking portion to make the first guide grooves inclined.20. The insulating film according to claim 3, wherein the bottom maskingportion is a trapezoid, and the length of the bottom edge of the bottommasking portion is greater than the length of the top edge of the bottommasking portion to make the first guide grooves inclined.